DC’s cold start to December

 

A seasonal view in Washington, D.C.

This December has gotten off to the coldest start in the nation’s capital in 20 years. Although no record lows have been set, the first 12 days have been colder than average. That’s led to DC’s monthly average temperature (combining daily highs and lows) to be more than eight degrees below average so far this month.

While DC has experienced several colder than average December’s since 2005, this month has become the first since then that the initial 12 days were colder than average. The first 15 days of December 2005 were all colder than average in the nation’s capital. This month could eclipse that mark with below average temperatures on track to continue into next week.  

Besides being colder than average, there’s something else that December 2009, December 2010 and December 2017 all have in common in the nation’s capital. Each of those months were also snowier than average. In fact, December 2009 was DC’s snowiest on record.

A total of 1.1” of snow has already fallen this month and that’s near the monthly average of 1.7”. Some light snow is on tap late tonight and tomorrow morning that could add to that total. It will also coincide with another push of arctic air with some of the coldest weather for tomorrow and Monday since last winter. 

Only one December day has seen record cold in the nation’s capital over the last 35 years (a record low-high of 22° on December 24, 2022). However, bitterly cold December days have been more frequent in the nation’s capital. For example, Christmas Eve 2022 had a high/low of only 22°/9°. That was also the last time Washingtonians experienced December temperatures in the single digits.

According to the National Weather Service, the last time the nation’s capital experienced consecutive December days with high temperatures at or below freezing was on December 28 – 29, 2017 (25°, 32°). The last time high temperatures in Washington, D.C. remained under 30° during the first half of December was December 14, 2010 (29°). The last time the nation’s capital experienced consecutive December days with high temperatures at or below freezing during the first half of December was on December 13 – 14, 2005 (32°, 26°). 

Longtime residents may recall that temperatures remained at or below freezing on five consecutive days in the nation’s capital from December 26 – 30, 1993, and on four consecutive days from December 10 – 13, 1995. Aside from being unusual, the cold start to this December has felt particularly cold since so many recent December’s have been warmer than average. 

No strong correlation exists, however, between periods of cold and snowy December weather and the winter season as a whole in the D.C. metropolitan area.